# BIC Expert Help

The first line is used for DCCT *Beam-on* logic.
If the DCCT current exceeds the*Low Beam Cutoff*, the beam is thought to
be ON, unless the logic is manually disabled. When the beam is on, the
current integrator runs.

The *Filled Bucket Threshold* is the limit above
which a bucket is counted as filled.

The internally calculated lifetime will not exceed
the *Maximum Calculated Lifetime *if it is non-zero. This stops absurdly large values from interfering with auto scaling.

The *Injection Spacing *is set to be the minimum
spacing such that injection at 60 Hz will not cause interference to a non
damped bucket.

The signals from the bunch-by-bunch current monitor are not always clean, but have signal "leaking" into subsequent buckets. The deconvolution procedure is described here.

# Time Base Calculations

The time basis used for lifetime calculations is derived from an analysis
of the DCCT beam currents. The *Actual Calculation *time is
the basis for the lifetime. This is determined by finding the longest
time for which the Calculated Chi squared is lower than the Chi squared
requirement.When the error is too large, the time basis is reduced by
the Time Base Reaction number. Possible time bases are selected from the
set of those currently stored. That set consists of 31 possibilities, with
a fibonacci-like distribution.

Hence, if the current time base is large
and needs to be reduced, the reduction will be large. With a reasonable
Chi squared constraint and a time base reaction of 2 or 3, the algorithm
adjusts quickly to changes in slope (new lifetimes).

A maximum value of the automatically chosen value can be set, or a manual
value can be set. The latter is useful when a fixed base is required for
a specific beam experiment.

The bottom of the display shows the MPG queue pointers

See the BIT3 help for MPG details.